Vapor burner



J an. 9, 1923. 1,441,639. F. L. SMITH.

VAPOR BURNER.

FILED JUNE 18, 1920. 2 SHEElS-SHET l.

INVENTOR.

A TTORNE Y.

Jan. 9, 1923.

F. L. SMITH.

VAPOR BURNER.

FILED JUNE 18. 1920.

2 SHEETS-SHEET 2" INVENTOR. Fbfl/m L 500 7w.

A TTURNE Y.

Patented Jan. 9, 1923.

rrsn STATES FRANK L. SMITH, OF DAYTON, OHIO.

VAPOR BURNER.

Application filed June 18, 1920. Serial No. 389,829.

mon to devices of its character, such as a receptacle into which the liquid fuel flows and wherein it is reduced to vapor by con-v tact with the hot walls of the receptacle, a combustion chamber into which the vapor rises, means for conducting air to the combustion chamber, etc. It'also comprises a diffuser, or what is frequently referred to as a wick. This diffuser is of novel con struction and not only performs the usual function of a wick, but it also serves a novel purpose in acting as an auxiliary vaporizer.

Another improvement consists in affording a free passage for the fuel to all parts of the vaporizer; this is efiected by providing a channel in which the fuel can flow entirely without hindrance from the dif fuser. 7

Another improvement consists in conducting air to a far larger area of the diffuser than has heretofore been possible, and another in conducting an unusually large volume of. air to the lower portion of the com- .bustion chamber.

Another'improvement resides in the provision of novel means for pre-heating the ""air' thatenters the combustion chamber and also in conducting heat to the lower portions of the burner, andespecially the vaporizer.

Another improvement resides in a novel arrangement for displacing and tilting the upper portion of the burner, so that a burning match can be applled to the diffuser; also in the construction of the priming tube.

'In the accompanying drawings I have shown the preferred embodiment of my in v ention, also certain modifications.

-Fig. 1 is a side elevation of my burner, showing it in place in aeooking stove, only a portion of the stove being shown, however.

Fig. 2 is a fragmental plan view of a portion of one form of vaporizer.

Fig. 3 is a fragmental elevation of the portion of the vaporizer shown in Fig. 2.

Fig. 4 is a fragmental View of one form of diffuser.

Fig. 5 is a front view of a portion of the top of the stove, together with the index plate by which the position of the fuel valve is indicated; also showing the orificeinto' which priming fuel may be introduced.

Fig. 6 is a fragmental view of another type of vaporizer than. that shown in Figs. 2 and 3;

Fig. 7 is an elevation of the burner, showing the upper part tilted to yield access to the diffuser for lighting purposes.

Fig. 8 is a plan view of the. burner in the condition shown in Fig. 7.

Referring now to Fig. 1, the'base of the burner, 10, is seen to rest on a bar 11, which is attached to the frame of the stove by means not shown, a strap 12 assisting in the security of the base to the bar. Mounted on this base by means of legs 13, is the vaporizer. As is usually the case the burner is circular, this being, for several reasons, the most desirable form, and while various terms hereinafter used may attribute circular form to it, it is to be understood that there is nothing in my present invention which necessitates the burner being circular. Therefore, while, for convenience I will refer to the burner as circular, it is to be understood that 1' do not'limit its embodiment to this or any other particular form.

The vaporizer is an annular trough formed by a vertical wall 14 and an outwardly flaring wall 15 (see also Fig. 6). At 16 a boss is formed on the wall 15 to receive a fuel pipe 1.7. The cross section of the trough at the junction of the walls l l'and 15 is rather small, so that a comparatively small quantity of fuel will be suflicient to flow the entire length of the trough. The wall 14 is reduced in thickness at 18, forming a shoulder a short distance above the bottom of the trough. At 19 the wall la is again reduced in thickness and at this point the vaporizer may be said to terminate and give way to a vertical tube 20. The interior of this tube has a number of inwardly extending radial ribs 21, which at their upper ends join an inwardly and downwardly extending annular flange 2.2. The ribs 21 extend down onto the wall 14. and serve to conduct heat down to the vaporizer. 1

An extension tube 25 rests on the tube 20,

v and has inwardlyextending to: ribsQl, -"Theup'p'er' 'endY-"of'ifthis extension is partially closed bya dome-27 having an 1 aperture '28 in its center. 'Ihis extension might beIm-adeintegral with the tubeQO and vaporizer, but for convenience it is made separableftherefrom. .The lower ends of the 1 r'ibsi'ae are obliqueand ofsuch length as to rest on the flange .22; the walls and are shaped so as to form .an interlocking -joint, as at 29 (see "Fig. 6); This allows the extension to be lifted off of the tube. 20 to give e'asyaccessto the vaporizer, while ins-u'ringa good connection between the parts when they are assembled. Both the .tube'20 of perforators may be used; simple holes,

lffifor example.

Resting on the edge of the wall l 5'of the vaporizer is a second cylinder 35, whichis provided with outwardly extendingradial ribs 36. The wall of this cylinder is slotted, as at 37, thus reducing it to a succession of annular rings,*which are united by "the ribs 36. The upper end of the cylinder terminat-es inanoutwardly extcndingfiange 38, and the whole cylinder is surrounded by-a j acke't 39, which at its upper end meets the flange'i3'8 vand at itslower end meetsthe upperedgeiof the'base "10. The baseis a bowl shaped-affair provided with a large opening for thegadmittance ofair. I Surrounding fiil'fthe upper portion of the cylinder35 is a hood or cap 4-1, which is supported by lugs 4=2 .that rest onthe flange 38. The hood is considerably larger in diameter than the jacket 39, so as to leave a liberal air space 43 between them, the lugs 42 holding the hood sufficiently above the flange 38 to form' a similar air -space at that point. The top of thehood is provided with an opening 44 approximately the size of the inner diameter of the cylinder 35.

Vapor'burners of the present class very commonly have a wick of some description, which is used in lighting the burner, but is practically useless thereafter. Instead of a wick I use what I call a diffuser, 50, which is made from a cord composed of loosely braided metallic wires. In fact, I have found the ordinary braided metal picture.

wire very satisfactory for this purpose. In Fig. 4 is shown one form of diffuser that I have found satisfactory, which i's a piece of picture wire bent into a series of triangular loops. A piece of this of suitable length .is

formed into a circular band that is placed around the portion of the vaporizer wall lying, above the shoulder 18. The band is of such width that'the upper horizontal sections lie approximately midway between the first and second slot 30in the cylinder 20.

Another, and possibly the preferred form of diffuser is shown in. Figs. 1 and 7,- whjere, in-

stead of the loops being triangular they are closely formed vertical loops, joined at the toplby horizontal portions similar to those of the type shown in Fig. 4.

Fuel is supplied to the burnerfroma res-.

ervoirnot shown, through a horizontal pipe 60, a valve-61 and pipe 17.

The operation of the burner will now be described: Having opened the valve 61 and allowedaquantity of 'fuel to flow into the vaporizer, a match isapplied to the diffuser and the fuel which has risen by capillary attraction is lighted; Figs. 7 and 8 show how the cylinder 35 and parts carried by it, may be lifted at one sideto give access to the diffuser for lighting. A handle 62 riveted to the-jacket 39 is provided for this purpose. and ears 63 riveted'to thebase 10 are provided for preventing the displaced parts being shifted too'far to the-rear. These ears are by no meansessential, however, as the inner cylinder serves much the same purpose.

It is to be noted that the diffuser is held some distance above the bottom of the trough by the shoulder 18, leaving a clear channel in which the fuel can quickly flow clear around the trough, thus distributing the fuel evenly to all sides of the burner. The firstinflux of fuel, which maybe called the priming charge, shouldbc of sufficient volume to submerge the. lower portion of' the diffuser. The loosely braided structure of the. diffuser endows it with great capillary power and the fuel is quickly raised by capillarity and spread over the surface of the diffuser in a thin film that is readily ig nited with a match. The flame thusproduced soon heats the parts of the burner to a temperature suflicient for vaporizing the fuel, and presently the fuel valve can be reopened and fuel regularly fed .to the burner in suitable quantities, as usual in burners of U this character.

The vapor rises in the space inner and outer perforated cylinders, which space is called the combustion chamber, and

through the slots 30 and 37," resulting in the emission of a fierce blue frame from the betweenthc 3 upper end of the combustion chamber. The

combustion begins low down in the charm-- her and becomes more and more complete as the vapor ascends and receive fresh sup-. plies of air through the several slots 30 and 37, until all of the fuel is consumed and there is produced what is often referred to there becomes mixed with air entering 1 vaporizer in the form of carbon, thus not only Wasting fuel, but forming a sort of insulating coatin Which prevents fresh fuel from receiving tie full benefit of the heat of the vaporizer. Thus the burner constantly becomes less and less efficient.

This is prevented in my burner by the intense heat of the vaporizer, several factors contributing to this result: Much heat is conducted down to the vaporizer by the ribs 26 and 21. The radial flange 22, being in the path of the air which enters at the opening 40 in the base 10, diverts a large volume of air to the lower slots 30 and thus produces a hot flame in the lower part of the combustion chamber. This effect can be modified more or less by variations in the Width of the flange. The ribs 36 of the outer cylinder also carry heat down to the vaporizer. Although the saw cuts 30 and 37 separate the cylinders into isolated rings, the ribs 21, 26 and 36, which are integral with the rings receive heat from the rings and carry it down to the vaporizer. Still another factor in the complete vaporization of the fuel is the freedom with which the fuel can circulate around the vaporizer, this being due to the diffuser not reaching to the bottom of the trough. As long as the fuel remains liquid it tends to flow along the trough, and in this way is brought into all parts of the hot vaporizer with much greater freedom and rapidity than is pos sible in other burners of which I am aware. The fuel naturally bubbles and sputters more or less as itcomes'in contact with the hot surfaces, so that even if its actual level is not sufficient to reach the diffuser after the priming charge has been consumed a great deal splashes up on the diffuser, which being metallic and very hot, the upper end -of it being very close to if not actually in the flame, assists very materially in the vaporization of the fuel. In fact, the diffuser becomes a sort of auxiliary vaporizer.

Air for the propagation of flame enters at the opening 40, part of it passing to the slots 30 as above described, and part passing below the vaporizer and into the space between the cylinder 35 and jacket 39, and thence into the combustion chamber through the slots 37. A portion of the air also issues from the opening 28 in the dome 27. This column of air has an important function in supporting the flame after it issues from the combustion chamber. The ribs 21 and 26 heat the air which enters the inner cylinder and ribs 36 heat the air which enters the slots 37. In fact, this air is very much heated, first by passing around the vaporizer and then by its comparatively close confinement inside of the jacket 39 and contact with the several hot surfaces. This preheating of the air is of considerable value in securing perfect combustion of the fuel. Air entering the air space 43 is heated more or less by the surrounding heated parts and is directed against the flame immediately after it issues from the combustion chamber. This very greatly augments the heat of the flame, so much so, in fact, that I call this column of air a blast. Its action is susceptible of modification by varying the proportions of the hood, such as lengthening or shortening the skirt or varying the size of the opening 44, but I have found the proportions shownv in Fig. 1 very eflective.

WVhile various fuels are burned with more or less success in burners of the character described, it has been found that few of the burners so far marketed are capable of burning kerosene satisfactorily, and it is doubtful if any of them eflect perfect combustion. For reasons which have been men tioned, my burner is entirely successful and satisfactor with kerosene as the fuel. Be-

test kerosene. Furthermore, because of the unique efiicacy of my improved diffuser it is quite practicable to start the burner by admitting a suitable quantity of kerosene through the valve 61 and lighting it at the diffuser. If, however, the operator desires to prime the burner with some other fuel it may be done by injecting the priming charge at an orifice 66, whence it is carried by a branch tube 64 to the pipe 17. Arrangements ofthis kind are not entirely new, but I believe an uninterrupted passage from the admission orifice tothe vaporizer is novel. I provide a cover 65 to set over the opening 44 when the burner is extinguished, which serves to suppress most if not all of the odor which commonly arises from burners of this kind after theyare extinguished. The odor is produced by certain residual fuel remaining in the burner, too little to maintain the flame, but enough to cause an odor in the room. By means of the cover this residual vapor is confined in the various parts of the burner until by the cooling of the burner the fuel againbecomes liquid and deposits itself on the surfaces in light film.

Some further consideration of'the diffuser is now desirable. Being made of loosely .is obtained even with the use of high firebraided other points, all of which produces a wires .it follows that the general direction of all the wires'is the same. That is, while the wires cross and recross each other in the braid they all have the same experience, namely, extending from one end to the other of the cord. The crossing and recrossing of the wires brings them into contact at numerous points, them in near-relation, one to another, at all condition most favorable to capillarity. And since the wires all run lengthwise in the cord', surfacecapillarity is added to that which is brought about by the intimate relations of. the several wires in the cord, the

' result being a-devicecapable of great capillary power. Referring to, Figure 6 it will be seen that the upper loops of the cord extend above the offset 19 and comprise oomparatively isolated horizontal sections of cord. which ab-utend on and form a practically continuous ring. Being between the lowermost and second slot 30 and free standing, i. e., removed from the wall 20, air entering at the slots is enabled, to circulate all around these: isolated sections of cord,

thereby oxygenating the fuel in the fullest and most efficient manner possible in a burner of this kind. This has been discovered to be a valuable feature in that it adds very materially to the effectiveness of the diffuser, especially in starting the burner. The free standing of the upper portion of the diffuser, also greatly facilitates lighting the oil on it with a match. On the other hand, the fact that the major portion of the diffuser lies against the wall l-l adds to its capillary power. This feature may be augmented, if desired by providing the wall with ribs 70, between which the close loops of the form of diffuser shown in Fig. 1 may lie. This modification is shown in Figs. 2 and 3.

What I claim is as follows:

1. In a vapor burner, a vaporizing trough, means for delivering liquid fuel thereto, and a capillary diffuser in said trough, whereby fuel is raised above its normal level, said diffuser, being composed of a braided metallic cord bent to form vertical loops whose lower ends become immersed in the liquid fuel in the trough; and means for conducting air to the upper endsof the loops.

2. A metallic capillary diffuser for vapor burners, composed of a plurality of small wires loosely associated, touching each other at frequent intervals but extending comparatively long distances more or less near together without touching each other, thereby endowing the diffuser with great capillary power, the several wires running substantially vertical through the greater part of their length.

3. A metallic capillary diffuser consisting of a group of small wires braided into a while keeping.

between said tubes forming a combustion chamber which is supplied with air by the perforations; and a capillary diffuser in the trough, which extends upward to a point above the lowermost line of perforations,

and there comprising a series of free standing vertical and isolated horizontal sections, around which air entering at said perforations can circulate.

5. A vapor burner comprising a vaporizer in the form of an annular trough, a perforated vertical tube carried by the inner wall of the trough, a second perforated vertical tube carried by the outer wall of the trough, the space between said tubes forming a combustionchamber which is supplied with air by the perforations, said perforations consisting of narrow horizontal slots; and a capillary diffuser consisting of a metallic cord bent to form a succession of loops which extend from the trough up to a point above the lower slot.

' 6. A vapor burner comprising a vaporizer in the form of an annular trough, a perforated vertical tube carried by the inner wall of the trough, a second perforated vertical tube carried by the outer wall of the trough,

the space between said tubes forming a combustion chamber which is supplied with air by the perforations, said perforations consisting of narrow slots; a capillary diffuser consisting of a metallic co-rd bent to form a succession of loops which extend from down in the trough to a point above the lowest perforations, the diffuser lying against one wall of the trough for a portion of its height and standing free from the wall for the remainder of its height. 1

7. In a vapor burner, a vaporizerfadiffuse-r lying against one wall thereof for a 1-15 portion of its height and free-standing therefrom for the remainder of its height, said diffuser comprising a succession of isolated vertical sections united at their upper ends by horizontal sections.

8. A vapor burner, comprising a vaporizer and inner and outer tubes between which is formed a combustion chamber, a jacket-outside of but separated from the outer tube by an air space, a blast hood outside of the whole. said hood having an opening around its skirt to admit air, and an opening at its top whereby air is delivered to the flame as it issues from the combustion chamber, and a cover to lay over the upper opening of the blast hood after the fuel supply is rut ol'f. leaving the skirt opening uncovered.

9. A vapor burner comprising an annular vaporizing trough. eoneentrio perforated tubes suppoxted thereby. one extending up from the inner and the other from the outer wall of the trough, the spare between said tubes constituting a (OfillHlStlOIl (-hamber whirl] reoeives air through the perforations; an annular flange in the inner tube intermediate its upper end and the trough, whereby a larger proportion of air is induced to pass through the lower perforations than would pass therethrough if said 15 flange. were absent. and vertical radial ribs extending downward from said flange to the trough, said ribs being integral With the flange, with the portions of the tubular wall it traverses and with the trough.

10. A metallic capillary diffuser, consisting of an elongate metallic member bent to form a succession of loops, the limbs of which lie substantially if not quite together, said loops being separated by sections of said member extending at right angles to the loops, the Whole being formed into a ring so that said intervening sections form a circle from which the loops extend laterally in the same direction.

FRANK L. SMITH. 

